In this study, Fe/ZnO composite nanosheets were successfully prepared by hydrothermal method using nanofibrillated cellulose (NFC) as a soft template. The crystalline and morphology structure of the samples were characterized by X-ray diffraction (XRD), BET analysis, Scanning electron microscopy (SEM) and Transmission electron microscope (TEM). Fe doping not only fabricated ZnO from square to strip shape, but also brought larger surface area and pore volume, resulting 59.7% removal of tetracycline by adsorption action. UV–Vis absorption test, X-ray photoelectron spectroscopy (XPS) and Energy dispersive spectrometer (EDS) have shown that iron had successfully embedded into the ZnO nanosheets resulting in red-shift of absorption wavelength. Fe/ZnO nanocomposites had about 90% photodegradation for tetracycline after two hours’ UV-irradiation.
The transmission of pathogenic bacteria via the contaminated surfaces of interactive touchscreens is an important route of infection. It is therefore imperative to develop a functional film with antibacterial properties to prevent cross-infection. In this paper, a bilayer thin-film structure composed of iron-doped and copper-doped zinc oxide (Fe-ZnO/Cu-ZnO) is synthesized through a spin coating technique based on sol-gel. The synergistic effects of metal ion doping, combined with the influence of the internal electric potential, during the photocatalytic reaction process, promote the separation and migration of photogenerated carriers. As a result, it notably boosts the photocatalytic properties. The nanofilm is demonstrated to achieve a rapid bactericidal effect (surpassing 90%) under sunlight irradiation. Furthermore, it is shown to completely kill bacteria after 20 min of illumination and to maintain excellent antibacterial performance (surpassing 90%) for a period of 30 days. Concurrently, the thin film displays both exceptional light transmittance (surpassing 90%) and noteworthy benefits, including environmental sustainability, cost-effectiveness, and the capacity for safe disinfection. The thin film exhibits considerable potential for implementation on surfaces subject to high-frequency public contact. It boasts extensive application prospects and serves as a foundational reference for the design of photocatalytic antibacterial thin films.
Xi Zhu,Zhikun Li,Bolong Liang,Shijie Xing,Hongbin He,Xiliang Li,Shu-Xuan Liang
The continuous contamination of ciprofloxacin (CIP) pharmaceutical residues poses a potential risk to the ecological environment and human health. Using semiconductor materials with optimized heterojunctions for photodegradation is an effective way for the CIP removal. In this study, Fe-ZnO/CdS Z-type heterojunction was synthesized, and used for the photodegradation of organic pollutants. The Fe-doping brought abundant surface oxygen vacancies to ZnO, which could effectively promote interfacial electron transfer. In addition, the valence transition of Fe (II)/Fe (III) could effectively participate in the redox cycle and improve the carrier transfer efficiency. The construction of Z-type heterojunction facilitated the separation of photogenerated carriers, and the photogenerated electrons in the conduction band of CdS reduced oxygen to produce superoxide radicals as the main active radicals. A series of photoelectric characterizations had proved that the introduction of CdS could effectively improve the visible light utilization rate and photogenerated carrier separation efficiency. The Fe-ZnO/CdS system achieved 90.0% degradation efficiency of CIP within 120 min under visible light. Impressively, Fe-ZnO/CdS heterojunction showed practical degradation capability in complex aqueous environments and excellent reusability. This study provided an effective strategy for the design of metal oxide-based photocatalysts and offered a new idea for the removal of drug residual contaminants.